Dexter d



@uitrit tetes getest ,@ffir;

IMPROVEMENT IN ROTARY PUMPS AND ENGINES.`

DEXTER D. HARDY, OF CINCINNATI, OHIO, ASSICrNOR` TO `THOMAS FOULDS, or SAME PLACE.

.Letters .Patent No. 60,365, dated December 11, 1866.

like rlgfhule :auch It in that intim ttmt ant making part 11i-tht same.

T() ALL WHOM IT MAY CONCERN:

Be it known that I, DEXTER D. HARDY, of Cincinnati, Hamilton county, in the Stateof Ohio, have invented 1. i a certain new and useful Improvement in Rotary Pumps and Engines; and I do hereby declare thefollowing to be a full, clear, and exact description thereof, reference being had to the accompanyingldrawing, making part of this specification. p A N My improvement is adapted specially forthe rotary pump and engine for which Letters Patent were granted to myself and John J. Morris, bearing date March' 5, 1861,A and consists in so constructing each revolving piston, that -its exterioror rubbing surface shall form opposing quarter circles of large and small diameter, the t large and small circles being connected by concave faces.

In the'accompanying drawing, A is the case or cylinder, B B the working pistons, and C the shafts, the latter being connected by the ordinary gearing, D D are the inner tongues or projectionsmhose oice is fully p explained in the patent above referred to, granted to myself and J'. J. Morris, March 5, 1861."

E is the induction, and F the eduction port for water or steam. I have discovered by practical experience i that the semi-cylindrical pistons, as covered by the above-mentioned patent, tend, by reason oftheir unbalanced character, to shake the pump or engine violently when running at high speeds, and cause the journalsand other working parts to wear out quickly. To eiectually remedy this defect, I construct the pistons,'B`B, of the form fully shown in the accompany drawing, a a', being opposing and balancing quarter circles, andb b opposp ing quarter circles of smaller diameter. To enable the pistons to work togethelgthe circles a d andi b b', are

connected by concave sides, c, whose concavity must be suiicient to enable the points of the pistons `to pass freely, and allow access for the water carried round in the concave sides, when inoperation. i

The form herein described is the -one preferred by me to ei'e'et the balancing of weight of the pistons, and

prevent shaking when in operation, but other inferior modiiicationswmay be employed, as fofiiistliice, three one-sixth circles, or four one-eighth circles, &c. I claim herein as new and of my invention.

The rotary pistons B B', whose peripheries are formed by quarter circles a a andb b', of dierent diameters, j connected by suitable sides c, in the described combination with the two central inner tongues D D', of the cioe l A., as and for the purpose specified.

In testimony of which invention, I hereunto set my hand. p

i DEXTER D. HARDY.`

Witnesses:

FRANK MILLWARD, JAMES H. LAYMAN. 

